datzenmike Posted August 6, 2018 Author Report Share Posted August 6, 2018 New oil gutter installed. This just directs thrown oil splash through the adapter plate to the rear case. Looking through my dozens of stripped down transmission pictures, not many have this in place. I think they are prone to fracture and falling out. Installed new rear seal. Not going to bother replacing the front counter bearing the old one is like new. Almost positive this is the source of the metal filings and chunk. 1 Quote Link to comment
datzenmike Posted August 12, 2018 Author Report Share Posted August 12, 2018 Too hot to work on this during the week. Got it all together and sealed up today. Getting the striking rod in the gate between all the shift forks was a total bitch. I slipped a spare shifter on so I get it. Stay in neutral, but twist over hard into the 5th/Rev gate and lower it on. Wiggle and pray. The cover front plate gasket survived but I lightly buttered it with RTV ? but at least it was black, and I greased the seal lips so it won't start up dry! Greased the input splines, pivot ball, clutch arm at the slave push rod and the clips for the release collar. The transmission is ready to go in minus the oil. Pulled the clutch off sliced and removed the pilot bushing and 'hammered' a new one in. Sanded the PP and flywheel surfaces to remove the glaze and put it back on using a 71B input spline to hold the clutch disc in place. So the car and transmission are now ready to be united. Quote Link to comment
datzenmike Posted August 19, 2018 Author Report Share Posted August 19, 2018 Using the new gasket I opened the port out to 1.5". The port inside is 1.38" so I blended inward about an inch so there is a venturi effect to speed up the air before the valve. Lots of room for improvement... The exhaust is different. It's under lots of pressure and wants out NOW. So I opened the door all the way. Quote Link to comment
datzenmike Posted August 19, 2018 Author Report Share Posted August 19, 2018 Pretty much done for grinding. Quote Link to comment
datsunfreak Posted August 20, 2018 Report Share Posted August 20, 2018 If you are using an exhaust manifold and gasket with one big open hole there, you might try knife edging the wall between the ports? Seen that done on a few engines and it should help... Quote Link to comment
datzenmike Posted August 20, 2018 Author Report Share Posted August 20, 2018 The gasket is one hole but the cast manifold is divided. not mine Looks like it could be narrower though. Quote Link to comment
datzenmike Posted August 25, 2018 Author Report Share Posted August 25, 2018 Tried using a valve with a cutter welded on it. Just chuck it in the drill and presto the valve has a lathe like rounding to cut away the shrouding. Yeah it didn't work but I know that now. Went back over what I had done previously and opened it up more. Quote Link to comment
datzenmike Posted September 1, 2018 Author Report Share Posted September 1, 2018 Valve lapping. The seats were all pretty good. Intakes were carboned up over a layer of ceramic tan. Probably began burning oil near the end of it''s life. Intakes had a hard 'ceramic' coating that was a bitch to scrape off. Used the drill to spin the valve while holding a box knife against it Then polished with sand paper. cc'd the combustion chambers. With all the unshrouding and what not they are all at 47. On a stock L20B this would be a 8.2. Trimming .5mm or 20 thou would bring it back up. I used a piece of plastic with a small hole off set near the edge and child's medicine syringe and some grease. Use the grease to seal the valves and the plastic to the head. Tilt the head so the air can get out the hole. Don't forget the spark plugs. Quote Link to comment
datzenmike Posted September 2, 2018 Author Report Share Posted September 2, 2018 I still have the Z24 that I had in my old 620. It's been sitting under a 620 hood and an umbrella for 4-5 years? I got it out of an '84 720 that was rolled, but when I took the automatic off the flex plate had '89 Hardbody' in crayon on it. So this was a Z24i converted over to work in an older Z24 truck Nice! I got it running and ran maybe two tanks of gas through it and it ran extremely well, no oil puffing, quiet and smooth. Such a waste sitting there as I cut the lawn around it. Well I moved it out and power washed it clean. Took the exhaust, 240mm flywheel and clutch, all the timing gear, oil pump and distributor out. Then the head and intake. Drained the oil. Saved all the parts and bolts. Crank pulley bolt was a 27mm deep socket and 1/2" ratchet hit with hammer twice and off it came. Pulley was about 40 light taps forward on the back side of the pulley. Easy peasey. All cylinders are as clean and cross hatched. Need timing cover set and a head gasket for a Z24. What would an LZ24 with 480 lift cam and 9.26 compression go like? Quote Link to comment
datzenmike Posted September 3, 2018 Author Report Share Posted September 3, 2018 710 oil pan off spare engine. Already has baffle, but can be improved. Quote Link to comment
datsunfreak Posted September 7, 2018 Report Share Posted September 7, 2018 On 9/2/2018 at 6:48 PM, datzenmike said: What would an LZ24 with 480 lift cam and 9.26 compression go like? If you can get good gas there, and crank up the static timing to around 12-14, nice. It would go very nice. Should make plenty of torque and still rev decent with all that head work. Quote Link to comment
datzenmike Posted September 8, 2018 Author Report Share Posted September 8, 2018 Ordered and just got my Z24 head gasket, valve seals, Z24 timing gasket set (includes the oil pump, distributor, water pump gaskets and the crank seal) and a pan gasket. Already have an L series manifold set. Rain this weekend but I want to lengthen my timing chain. I have the engine waiting with an old gasket and a spare L head mocked up. Want to fit a chain and see how many more links are needed to close the loop. I noticed the Z24 tensioner has an oil bleed hole on top to lube the chain. I also noticed that the Z24 does not have an oil jet between the chain just beside the tensioner. It's been mentioned that Nissan dropped using this oil jet because not needed, when in reality it wasn't needed because the tensioner now does this job? When cleaning the L head I see there is an oil hole squirting oil on the cam sprocket from the front cam tower. Never noticed this before. I already have a Hardbody high volume oil pump so will keep both. To make things easier I will get it running on a stock L20B cam and then decide if the re-grind is worth trying. If I had the correct lash pads that is. Quote Link to comment
datzenmike Posted September 8, 2018 Author Report Share Posted September 8, 2018 So one of the hardest things to deal with is how to lengthen the timing chain but it turns out to be the easiest. JG used a pair of Mercedes master links to lengthen his chain. I can't be bothered dealing with a dealership 60 miles away that may not have them and also want $15 each. To split the chain I very carefully ground the peened 'rivet' head off the pin and punched it out easily. Save the pins I installed the chain on the sprockets of my mock up to see how many links were actually needed. Turns out it's two links all together. I sanded the cut ends of the pins (they are HARD) so they were very slightly tapered and tapped them back in place. MIG'ed in place. Boom! Took under an hour..... and now it's raining. Quote Link to comment
datzenmike Posted September 9, 2018 Author Report Share Posted September 9, 2018 I originally used an old L head gasket to define the limits of my unshrouding of the calves. I will definitely use a Z24 gasket for the wider 89mm bore, so I slipped it on and traced with magic marker. Turns out there is a LOT of material that can be removed. My compression right now, with 47cc chambers, is 9.26 so lots of room for improvement. I won't be taking that ring around the rest of the cylinder away. That part will remain a beneficial, though small, quench area. Quote Link to comment
datzenmike Posted September 10, 2018 Author Report Share Posted September 10, 2018 Valve shrouding boundary pushed back even further.... Quote Link to comment
datzenmike Posted September 12, 2018 Author Report Share Posted September 12, 2018 Ok all combustion chambers un-shrouded and cc'd. It's 48cc more or less. I'm calculating it as 49 just to be safe. That's 9.039 or again, to round down, 9 even although it's slightly higher. Quote Link to comment
datzenmike Posted September 16, 2018 Author Report Share Posted September 16, 2018 Spent a few hours today cleaning and de-greasing the outside of the block and spraying with engine enamel. Then power washing the timing cover and the head to remove any aluminum dust or valve grinding compound. Gave the cam a good spray to be sure the oil holes are clear as well as the oil feed holes in the head. I then assembled the new valve seals on the valves, springs and retainers and the cam and rockers, all well greased. Tomorrow I have to clean out the coolant passages in the block and clean the old gasket surfaces. Weather dependent. Quote Link to comment
datzenmike Posted September 16, 2018 Author Report Share Posted September 16, 2018 Shitty weather so cleaned up and prepared the timing cover to at least get something done today. This is a Z series timing cover so had to go through my stash for a proper L series lower rad inlet that also has the smaller hose fitting for the by-pass hose. Fortuitously I had a timing cover seal so pounded it in as well. The pump cavity has some minor erosion from cavitation. I dressed it with a wire wheel and filled it in with JB. That shit has to be at least as hard as aluminum. I'll sand it down later. The oil passage from the block pick up tube to the oil pump inlet goes through the timing cover.... but it looks like someone drilled two holes that sort of hit each other. There''s a large casting flash lip and sharp edge. I ground and sanded them down, can't hurt the flow. Between raindrops I pulled the block drain and hosed out the rust. The heads off so I blasted every opening in the top of the block, the drain and the heater hose spigot and with the timing cover also down into the front. The block is sitting with the flywheel end down. Quote Link to comment
datzenmike Posted September 18, 2018 Author Report Share Posted September 18, 2018 Cleaned off the old gasket material on the block for the timing chain and wire wheeled the block surface for the head gasket. There's a small amount of erosion so will probably use something like copper coat to be sure it seals. Finished with cleaning the oil pan surface. Damn I don't remember this taking so long when I was younger! Maybe I didn't go to as much trouble? Quote Link to comment
datzenmike Posted September 22, 2018 Author Report Share Posted September 22, 2018 Damn rain and it's almost dark when I get home. Got a wedge made and put the timing chain on right. Then the timing cover. Still have the oil pan and head but what to do about the head bolts? All the L series stick out about 0.65" not even counting the head gasket. I measured the Z24 block holes and they are 1.5" to 1.8" deep. Some thread near the gasket surface some are over 1/2" down inside the block. Some L head bolts don't even start to thread. Well I used the long cam tower bolts in place of the 6 short ones and bought 4 cam tower bolts that are 1" longer. I have tons of washers and will make sure they don't bottom out. Another thing, there is a missing coolant hole in the block above where the L head has the fuel pump. Two holes close together actually but I'll drill one out to feed the head and grind a groove in the aluminum head to join to the second hole. I would drill the block but the Z24 doesn't have enough metal in this area. I would drill a second hole but it would be right on the edge of the Z24 block. You can see the L head has a bump out there. So I have decided to JB weld it half closed. It's just too close to the edge of the block below it. I wonder if the Z22 is the same way... Z22... Z24... If anything it bumps inward where the hole in the head is above it. Well the Z22 and I guess the Z20 block still has the bump out even if the hole is not used but the Z24 doesn't have it. If putting an L head on a Z24 block better have a look at this. This should work once filed down flat..... and I have some of that spray on Permatex copper gasket maker/sealant. Quote Link to comment
datzenmike Posted September 24, 2018 Author Report Share Posted September 24, 2018 Nice and sunny and not too hot. Put in 8 hr.s getting it right. Center punched and drilled the Z24 block to send water up into the L head beside the fuel pump. Then joined the two holes in the head. You can see the JB Weld I added to the hole to support the gasket so close to the edge of the block. Also found a huge hole at the rear of the L head that needed to be drilled out on the Z24 block. I decided to do away with the L20B timing cover and having to seal the 3/4" between it and the underside of the L head. Instead I'm using the Z24 timing cover and plonking the L head right on top. That little crescent of JB Weld is the closest the Z24 head gasket comes to not sealing. Had to math to figure out how many washers are needed to grip as many threads as possible but not bottom out. The holes are all different depths and some threads in the block start 1/2" down. Permatex copper gasket maker. When the cam sprocket went on it was a way to the left of the V. I re-set one tooth and the V was too far to the right. Ended up on #1 hole. To do... Bolt the engine brackets on. Put a spare oil pressure sender on. Mod the oil pan and install. Install the high volume KA oil pump. Spin the pump with a drill and prime the oil system. Clean and polish one of the half dozen valve covers I have and install. (nice winter job) Think about what flywheel I want to use. The 710 is using the only 200mm I have, but I have 7-8 225mms and a couple of 240mm. Figure out what flywheel and clutch to use. Quote Link to comment
datzenmike Posted October 9, 2018 Author Report Share Posted October 9, 2018 OK I done did something experimental and should have known better. Head bolt snapped off, so removed head. Going to try to find 4 studs the correct length for the 4 longer cam tower head bolts. I'm in the process of cleaning the copper coat mess off the head and block surfaces. Engine never started so it did not stick to or damage the gasket so it's re-usable and only has a slight impression in it. While it's off I checked the warp, and good thing I did. It's 0.015" where 0.004 is barely a pass. I used a SS drafting straight edge from work. The cam turns beautifully so the warp seems to be down on the block mating surface. Like all the thin spaces between cylinders have raised up away from the block. Got some ideas on fixing this. Quote Link to comment
datzenmike Posted October 14, 2018 Author Report Share Posted October 14, 2018 Warp head cure documented here... https://ratsun.net/topic/74560-warped-head-cure/?tab=comments#comment-1586430 Now can work on the head bolts. Well studs now I think. Got the 4 long ones finished and probably one short. Just 4 more to go... What does ARP charge for them???? Also I have a set of main and rod bearing, new, that I bought years ago for another project. When I get the head back on I can turn the crank and get them in. Quote Link to comment
datzenmike Posted October 21, 2018 Author Report Share Posted October 21, 2018 Popped the mains caps off tapped the old upper with screwdriver blade and rotated the crank and out they came. Greased this one and reversed the crank while pushing it, and in it went. Generally in good condition... For anyone that thinks the oil drains off the bearings when sitting for 5 years... Rods were easier and again basically the same condition. Quote Link to comment
datzenmike Posted October 28, 2018 Author Report Share Posted October 28, 2018 This time I copper coated the gasket. There were 2 holes that needed to be punched into the gasket so just as well I took it back apart. The torque wrench was way way out of whack also. Like 30 ft lbs instead of 60. It's been in the box for 10 years ever since I bought it so had to calibrate it on a crank pulley bolt. Anyway head on and torques tight. Had to fuck with the sprocket to get the cam timing mark just to the left of the V... I think #3? The glass and sandpaper worked good on these items, a '79-'80 thermostat housing and cover. The TVV on the side is no good to me (also broken) so I found a hex plug off a KA intake and blocked it off. The by pass fitting was also not great so again found something from the KA engine... I also spent this afternoon dismantling my high volume KA oil pump, cleaning it and putting a new gasket on it. It was in excellent shape. I could smell WD-40 so I guess I sprayed it before storing it. Sanded down the body as well. Ready to install. Weather permitting I'll make cereal box gaskets for the thermostat and install . Quote Link to comment
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